The University of California, Irvine will serve as the echocardiography reading center for the Coronary Artery Risk Development in Young Adults (CARDIA) Study which is a study of the distribution and change in risk factors during young adulthood in black and white men and women. The baseline CARDIA examination began in June 1985 with the goal of recruiting and examining 5,000 men and women aged 18-30 years in four communities. Participants were selected from the total population, selected census tracts or, in the case of one Center, the membership of a large health plan. Participants were successfully selected to obtain a cohort with approximately equal representation by blacks and whites, men and women, those aged 18-24 and 25-30, and those with no more than a high school education and more than a high school education. The study involves a Coordinating Center (which subcontracts for the Pulmonary Function Reading Center and the Central Lipid Laboratory), four field Centers and the Echocardiography Reading Center. A baseline echocardiography was performed during the Year 5 examination and this performance period will allow for an additional examination and further longitudinal analysis of the cohort during the Year 10 examination on cohort participants at two of the four field centers. The main objective of the echocardiography compent is to describe and identify determinants of change in left ventricular mass.